1. Field of the Invention
The present invention relates to a semiconductor device and a manufacturing method of a semiconductor device.
2. Related Art
In recent years, the MOSFETs having the so-called vertical double gate structure have been developed as MOSFETs having a three-dimensional structure. Among them, MOSFETs having a semiconductor layer formed so as to take the shape of a fin are called fin FETs.
In the case of such fin FETs, silicide for reducing parasitic resistance is formed on a surface of a source/drain region by consuming a semiconductor layer made of silicon.
In the fin FETs, therefore, it is necessary to ensure a region where silicide is to be formed while attempting to make elements finer. Therefore, a raised semiconductor layer is formed by raising wholly a surface (a top face and side faces) of a semiconductor layer which is not covered by a gate electrode and a side wall insulation film toward the outside. Thereafter, a source/drain region and silicide are formed one after another.
At that time, the raised semiconductor layer is formed by using the vapor phase epitaxy method. In the vapor phase epitaxy method, however, there is a problem that the semiconductor layer cannot be grown homogeneously. This is because a crystal plane having a desired crystal orientation cannot be formed on side faces of the raised semiconductor layer and a facet which is a specific stable crystal plane depending upon the film forming condition is formed.
For example, even if it is attempted to form a raised semiconductor layer having side faces which are <110> in crystal orientation, the use of the vapor phase epitaxy method poses a problem that a facet which is <111> in crystal orientation is formed on the side faces of the raised semiconductor layer.